This invention relates to a multi-purpose panel system which is assembled from precision-made components and has superior mechanical properties. More specifically, the panel system is lightweight and very stiff or self-supporting, utilizes components formed from sheet material and has a low cost of assembly.
Various types of sandwich construction panel systems are known. However, these typically employ relatively heavy internal frame components such as channel members and the like that are bent or otherwise formed to the required shape. Also, such systems may be adapted or have been developed for use only in a specific application, such as for aircraft fuselage paneling.
Sandwich flooring systems in present use may have other disadvantages. For instance, they may require a structural underframe to provide sufficient support, depending upon the load to be carried or supported. Other sandwich configurations may have adequate stiffness or rigidity for floor or wall system applications, but they are typically relatively heavy and difficult to assemble.
Accordingly, a primary object of the subject invention is to provide a lightweight and strong structural panel system including first and second spaced skins and a web core therebetween constructed from sheet material that secures the skins together in a spaced relationship and provides an interlocked supporting grid between the skins.
Another important object of the subject invention is to provide a panel system as aforesaid having a web core that includes a plurality of spaced apart longitudinal and transverse core members which are precision formed of either metal or rigid plastic to fit easily together and thereby present a stiff, rigid, self-supporting structure.
Still another important object is to provide such a panel system of metal construction having core members provided with longitudinally spaced projections which extend through openings in the panel skins to provide self-fixturing during assembly and welded connections in the final product.
Yet another important object is to provide the aforesaid metal panel system with twin projections or tabs at each welded connection to the skins so that one tab may be used to secure the skins and core together in a fixed relationship at a connection site while welding is initiated at the other tab, whereby conductive metals such as aluminum may be welded without the need for elaborate fixtures during assembly.
Furthermore, another important object of the subject invention is to provide a panel system which, in addition to superior strength and rigidity, has good insulation properties and provides an interior core space that can be used as a duct for fluid flow, evacuated to provide a partial vacuum, or filled with a liquid, particulate material or other fluid as desired for a particular system application.
Another object is to provide such a panel system in which the components thereof may be assembled and produced with close tolerances utilizing simple tooling, thereby assuring that panel sections will be uniform so that they can be readily joined together to present a composite structure of the desired physical size.
Another object is to provide a panel system that is usable in a variety of applications, such as in the construction of any type of cargo carrier (e.g., railroad cars, aircraft and ships), general purpose enclosures and structures, storage tanks and the like.
Still another object is to provide a panel system usable for a variety of purposes, such as wall paneling, flooring, and applications requiring structural reinforcement, superior insulation properties and/or ductwork provided within the panels themselves.
Still another object of the subject invention is to provide a paneling system that when used as flooring does not require a structural underframe.
Still another object is to provide a structural system composed of panel sections which are relatively small and easy to handle, and which are readily connected together to provide a final structure of the desired size and configuration.
Yet another important object of the subject invention is to provide such a paneling system that is strong, rigid, lightweight and easy to assemble as aforesaid, and which does not require the use of mechanical connectors.
These objects are attained by providing a paneling system comprising a first skin, a second skin, a web core of sheet material construction for supporting the skins in a spaced relationship, and means for securing the panel components together while providing self-fixturing during fabrication of the panel. The web core includes a plurality of spaced apart longitudinal members having longitudinally spaced singular or twin projections or tabs extending therefrom and transversely aligned, longitudinally spaced slots therein, and further includes a plurality of spaced apart, transverse cross members of similar configuration each having spaced slots therein receiving the longitudinal members at corresponding transversely aligned slots thereof to provide an interlocked grid between the first and second skins. The projections or tabs on the members extend through slits in the skins to provide a means to precisely locate the components during assembly and to join the core and skins together by welding when metallic material s are utilized.